On a small base (like a graph where the initial datapoints are less than 1/27th the ending datapoints), even large percentages can be hard to see. And I'm not sure how you can be agreeing 'exactly', since the Roman empire was as agriculturally based as anything else around (latifunda, panem et circenses, the Egypt grain tribute etc.).
But you are right that the annual growth due to efficiency was relatively small:
> Indeed generations of English schoolchildren have read, probably with bored bemusement, of the exploits of such supposedly heroic innovators as Jethro Tull (author in 1733 of An Essay on Horse-Hoeing Husbandry), “Turnip” Townsend, and Arthur Young. But this agricultural revolution is a myth, created by historians who vastly overestimated the gains in output from English agriculture in these years.4 The productivity growth rate in agriculture was instead modest, at 0.27 percent per year, lower than for the economy as a whole. But even these modest gains represented considerably faster productivity growth than had been typical over the years 1200–1800. Figure 12.4, for example, shows wheat yields per seed sown in England from 1211 to 1453. Medieval agriculture seems to have been totally static over hundreds of years.
(Clark remarks elsewhere that agricultural productivity growth is more like 1 or 2%, and the Chinese had easily double England's agriculture efficiency, but because farming is a war against entropy, with land being damaged and local pests adapting etc., the net productivity growth is small.)
Economic growth came mostly from population growth and exploiting additional natural resources.
But you are right that the annual growth due to efficiency was relatively small:
> Indeed generations of English schoolchildren have read, probably with bored bemusement, of the exploits of such supposedly heroic innovators as Jethro Tull (author in 1733 of An Essay on Horse-Hoeing Husbandry), “Turnip” Townsend, and Arthur Young. But this agricultural revolution is a myth, created by historians who vastly overestimated the gains in output from English agriculture in these years.4 The productivity growth rate in agriculture was instead modest, at 0.27 percent per year, lower than for the economy as a whole. But even these modest gains represented considerably faster productivity growth than had been typical over the years 1200–1800. Figure 12.4, for example, shows wheat yields per seed sown in England from 1211 to 1453. Medieval agriculture seems to have been totally static over hundreds of years.
(Clark remarks elsewhere that agricultural productivity growth is more like 1 or 2%, and the Chinese had easily double England's agriculture efficiency, but because farming is a war against entropy, with land being damaged and local pests adapting etc., the net productivity growth is small.)
Economic growth came mostly from population growth and exploiting additional natural resources.